On Thu, 12 Dec 2024 20:48:38 +0200 (EET)
Ilpo Järvinen [off-list ref] wrote:

On Thu, 12 Dec 2024, Ilpo Järvinen wrote:

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On Wed, 11 Dec 2024, Jonathan Cameron wrote:
  

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On Fri, 13 Sep 2024 17:36:30 +0300
Ilpo Järvinen [off-list ref] wrote:
  

quoted

pcie_read_tlp_log() handles only 4 Header Log DWORDs but TLP Prefix Log
(PCIe r6.1 secs 7.8.4.12 & 7.9.14.13) may also be present.

Generalize pcie_read_tlp_log() and struct pcie_tlp_log to handle also
TLP Prefix Log. The relevant registers are formatted identically in AER
and DPC Capability, but has these variations:

a) The offsets of TLP Prefix Log registers vary.
b) DPC RP PIO TLP Prefix Log register can be < 4 DWORDs.

Therefore callers must pass the offset of the TLP Prefix Log register
and the entire length to pcie_read_tlp_log() to be able to read the
correct number of TLP Prefix DWORDs from the correct offset.

Signed-off-by: Ilpo Järvinen <ilpo.jarvinen@linux.intel.com>  

Trivial comments below
Reviewed-by: Jonathan Cameron <Jonathan.Cameron@huawei.com>

Would have been nice if they'd just made the formats have the
same sized holes etc!  

That's not even the worst problem.

They managed to copy-paste most of the stuff into DPC (copy-paste is 
really obvious because the text still refers to AER in a DPC section :-)) 
but forgot to add a few capability fields into the DPC capability, most 
importantly, the bit that indicates whether TLP was logged in Flit mode
or not And now we get to keep the pieces how to interpret the Log 
Registers (relates to the follow up series). :-(
  

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diff --git a/drivers/pci/pcie/tlp.c b/drivers/pci/pcie/tlp.c
index 65ac7b5d8a87..def9dd7b73e8 100644
--- a/drivers/pci/pcie/tlp.c
+++ b/drivers/pci/pcie/tlp.c

@@ -11,26 +11,65 @@  

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 /**
  * pcie_read_tlp_log - read TLP Header Log  

Maybe update this to read TLP Header and Prefix Logs  

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  * @dev: PCIe device
  * @where: PCI Config offset of TLP Header Log
+ * @where2: PCI Config offset of TLP Prefix Log  

Is it worth giving it a more specific name than where2?
Possibly renaming where as well!  

Sure, why not.  

Hi again,

After doing this rename, I rebased the Flit mode series on top of it and
realized there's one small problem with naming where2. It will be 
overloaded between TLP Prefix Log (Non-Flit mode) and extended TLP Header 
Log (DW5+) (Flit mode) so I'm not sure if there's really going to be a 
good name for it.

Ah. I should read that series ;)

Absolutely fine - sometime generic naming is the best we can do!

Jonathan